/*
 * drivers/net/bond/bond_options.h - bonding options
 * Copyright (c) 2013 Nikolay Aleksandrov <nikolay@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#ifndef _NET_BOND_OPTIONS_H
#define _NET_BOND_OPTIONS_H

#define BOND_OPT_MAX_NAMELEN 32
#define BOND_OPT_VALID(opt) ((opt) < BOND_OPT_LAST)
#define BOND_MODE_ALL_EX(x) (~(x))

/* Option flags:
 * BOND_OPTFLAG_NOSLAVES - check if the bond device is empty before setting
 * BOND_OPTFLAG_IFDOWN - check if the bond device is down before setting
 * BOND_OPTFLAG_RAWVAL - the option parses the value itself
 */
enum {
	BOND_OPTFLAG_NOSLAVES	= BIT(0),
	BOND_OPTFLAG_IFDOWN	= BIT(1),
	BOND_OPTFLAG_RAWVAL	= BIT(2)
};

/* Value type flags:
 * BOND_VALFLAG_DEFAULT - mark the value as default
 * BOND_VALFLAG_(MIN|MAX) - mark the value as min/max
 */
enum {
	BOND_VALFLAG_DEFAULT	= BIT(0),
	BOND_VALFLAG_MIN	= BIT(1),
	BOND_VALFLAG_MAX	= BIT(2)
};

/* Option IDs, their bit positions correspond to their IDs */
enum {
	BOND_OPT_MODE,
	BOND_OPT_PACKETS_PER_SLAVE,
	BOND_OPT_XMIT_HASH,
	BOND_OPT_ARP_VALIDATE,
	BOND_OPT_ARP_ALL_TARGETS,
	BOND_OPT_FAIL_OVER_MAC,
	BOND_OPT_ARP_INTERVAL,
	BOND_OPT_ARP_TARGETS,
	BOND_OPT_DOWNDELAY,
	BOND_OPT_UPDELAY,
	BOND_OPT_LACP_RATE,
	BOND_OPT_MINLINKS,
	BOND_OPT_AD_SELECT,
	BOND_OPT_NUM_PEER_NOTIF,
	BOND_OPT_MIIMON,
	BOND_OPT_PRIMARY,
	BOND_OPT_PRIMARY_RESELECT,
	BOND_OPT_USE_CARRIER,
	BOND_OPT_ACTIVE_SLAVE,
	BOND_OPT_QUEUE_ID,
	BOND_OPT_ALL_SLAVES_ACTIVE,
	BOND_OPT_RESEND_IGMP,
	BOND_OPT_LP_INTERVAL,
	BOND_OPT_SLAVES,
	BOND_OPT_TLB_DYNAMIC_LB,
	BOND_OPT_AD_ACTOR_SYS_PRIO,
	BOND_OPT_AD_ACTOR_SYSTEM,
	BOND_OPT_AD_USER_PORT_KEY,
	BOND_OPT_NUM_PEER_NOTIF_ALIAS,
	BOND_OPT_LAST
};

/* This structure is used for storing option values and for passing option
 * values when changing an option. The logic when used as an arg is as follows:
 * - if string != NULL -> parse it, if the opt is RAW type then return it, else
 *   return the parse result
 * - if string == NULL -> parse value
 */
struct bond_opt_value {
	char *string;
	u64 value;
	u32 flags;
};

struct bonding;

struct bond_option {
	int id;
	const char *name;
	const char *desc;
	u32 flags;

	/* unsuppmodes is used to denote modes in which the option isn't
	 * supported.
	 */
	unsigned long unsuppmodes;
	/* supported values which this option can have, can be a subset of
	 * BOND_OPTVAL_RANGE's value range
	 */
	const struct bond_opt_value *values;

	int (*set)(struct bonding *bond, const struct bond_opt_value *val);
};

int __bond_opt_set(struct bonding *bond, unsigned int option,
		   struct bond_opt_value *val);
int bond_opt_tryset_rtnl(struct bonding *bond, unsigned int option, char *buf);

const struct bond_opt_value *bond_opt_parse(const struct bond_option *opt,
					    struct bond_opt_value *val);
const struct bond_option *bond_opt_get(unsigned int option);
const struct bond_option *bond_opt_get_by_name(const char *name);
const struct bond_opt_value *bond_opt_get_val(unsigned int option, u64 val);

/* This helper is used to initialize a bond_opt_value structure for parameter
 * passing. There should be either a valid string or value, but not both.
 * When value is ULLONG_MAX then string will be used.
 */
static inline void __bond_opt_init(struct bond_opt_value *optval,
				   char *string, u64 value)
{
	memset(optval, 0, sizeof(*optval));
	optval->value = ULLONG_MAX;
	if (value == ULLONG_MAX)
		optval->string = string;
	else
		optval->value = value;
}
#define bond_opt_initval(optval, value) __bond_opt_init(optval, NULL, value)
#define bond_opt_initstr(optval, str) __bond_opt_init(optval, str, ULLONG_MAX)

void bond_option_arp_ip_targets_clear(struct bonding *bond);

#endif /* _NET_BOND_OPTIONS_H */
value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/decnet/dn_timer.c?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/decnet/dn_timer.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/decnet/dn_timer.c?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net/decnet/dn_timer.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/decnet/dn_timer.c?h=nds-private-remove&amp;id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/decnet/dn_timer.c?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e&amp;id2=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.

It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server.  The call chains were different:

 - VT ioctl(KDSETMODE, KD_TEXT):

    intel_cleanup_plane_fb+0x5b/0xa0 [i915]
    drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
    intel_atomic_commit_tail+0x749/0xfe0 [i915]
    intel_atomic_commit+0x3cb/0x4f0 [i915]
    drm_atomic_commit+0x4b/0x50 [drm]
    restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'net/decnet/dn_timer.c')</div><table summary='diffstat' class='diffstat'>